| ObjectiveTo explore the impact of Hb A1 c level and clinical history of patients with type 2 diabetes mellitus on the structure of Hemoglobin(Hb). And also investigate the relevance between several influencing factors, which including occupational labor intensity and personal diet behavior and other environmental related factors, and the development of type 2 diabetes mellitus. Methods(1) The case-control study was carried out. All subjects were filtrated and enrolled according to relevant standards. All subjects in our study were the Han nationality without any differences in the race and gender. Two hundred and eighty-six patients with type 2 diabetes, including 152 cases of males and 132 cases of females, whose average age is 56.42±11.57 years, were enrolled as the type 2 diabetics group(T2DM group). Two hundred and ninety healthy people, including 158 males and 132 females, whose average age is 55.83±10.31 years, were enrolled as the healthy controlled group. Relevant information of subjects including general personal information, occupational information in details and personal diet behavior et al, were collected through the questionnaire survey. Patient history of type 2 diabetics was also used for assisting analysis. Single factor logistic regression analysis and multi-factor logistic regression analysis were used to filtrate and find the environmental influencing factors that associating with type 2 diabetes mellitus.(2) Thirty-eight healthy people from the first part subjects were enrolled as the healthy controlled group [group H, 20 males/ 18 females, average age 55.47±11.46 years]. One hundred and fourteen patients with type 2 diabetes were classified into the following three groups according to their Hb A1 c levels: group A, patients with good glycaemic control [n=36, Hb A1 c < 7.0%, 18 females/18 males, mean age 52.78±10.34 years]; group B, patients with general glycaemic control [n=40, 7.0% ≤ Hb A1 c < 9.0%, 18 females/22 males, mean age55.71±11.60 years]; group C, patients with sustained hyperglycaemia [n=38, Hb A1 c level ≥9.0%, 17 females/21 males, mean age 62.15±12.48 years]. Blood samples were collected by venepuncture after a 8 h overnight fast into a vacutainer with EDTA-K2. Blood biochemical indexes were measured and Hb were separated and purified from the blood samples. Uv-vis absorption spectroscopy technique and Fourier Transform Infrared Spectroscopy(FTIR) technique were used to obtain the secondary and tertiary structure information of Hb from the controlled group(group H) and diabetic groups(group A、B and C). The absorption of absorption peak intensity, relative peak intensity ratio and secondary structure content of Hb from each groups were compared.(3) Thirty-eight healthy people from the first part subjects were enrolled as the healthy controlled group [group H, 20 males/18 females, average age 55.47±11.46 years]. One hundred and twenty patients with type 2 diabetes were classified into the following three groups according to their clinical history: patients with clinical history < 5 years, group D [n=38, 18 males/20 females, average age 53.24±10.34 years]; 10 years ≤ patients with clinical history < 20 years, group E [n=42, 22 males/20 females, average age 58.10±13.69 years]; patients with clinical history > 20 years, group F [n=40, 22 males/18 females, average age 53.24±10.34 years]. Blood samples were collected by venepuncture after a 8 h overnight fast into a vacutainer with EDTA-K2. Blood biochemical indexes were measured and Hb were separated and purified from the blood samples. Uv-vis absorption spectroscopy technique and FTIR technique were used to obtain the secondary and tertiary structure information of Hb from the controlled group(group H) and diabetic groups(group D、E and F). The absorption of absorption peak intensity and secondary structure content of Hb from each groups were compared. Results(1) Results of single factor logistic regression analysis and multi-factor logistic regression analysis showed that occupational labor intensity, personal diet behavior, and obesity were related to the pathogenesis of type 2 diabetes(P<0.05). Increasing the occupational labor intensity appropriately could reduce the onset risk of type 2 diabetes(OR=0.325, 95% confidence interval is 0.129~0.817), however, unhealthy personal diet behavior(OR=1.063, 95% confidence interval is 1.063~3.543) and obesity(OR=3.550, 95% confidence interval is 2.704~6.432) might increase the onset risk of type 2 diabetes mellitus.(2) According to the results of studying the impact of Hb A1 c level on the structure of Hb, there was no obviously difference between group H and group A in the ultraviolet-visible absorption spectra. Although there were no obviously difference in the spectral pattern and spectral peaks between group H and diabetic groups(group B and C), the absorbance values of characteristic absorption peak among the three groups have significantly changed. Comparing to group H, the absorbance values of Hb located at 276 nm in groups B and C have statistically significant increased(P<0.05). However, the absorbance values of Hb located at 414 nm, 540 nm and 576 nm have statistically significant decreased(P<0.05). Among diabetic groups, there were statistically significant differences in the absorbance values of Hb between group A and groups B and C. Comparing to group A, the absorbance values of Hb located at 276 nm in groups B and C have statistically significant increased(P<0.05), but the absorbance values of Hb located at 414 nm, 540 nm and 576 nm have statistically significant decreased(P<0.05). What’s more, the absorbance values of Hb in group C also showed significantly difference when comparing to groups A and B. The absorbance values of Hb located at 414 nm, 540 nm and 576 nm in groups A, B and C have shown a trend of decreasing along with the increasing Hb A1 c level. There were no obviously changes in the second derivative infrared spectroscopy, Fourier deconvolution spectra, relative peak intensity ratio and secondary structure content of Hb in group H and group A(P>0.05). The relative peak intensity ratio I2960/I2874 and I1654/I1541 in groups B and C have significantly decreased along with the secondary structure content alterations of Hb. Content of α-helix secondary structure have shown significantly decreased in group C, but the β-sheet secondary structure significantly increased when comparing to groups A and B(P<0.05).(3) When studying the impact of clinical history on the structure of Hb, we found that there were no significantly changes in the ultraviolet-visible absorption spectra and FTIR spectra of Hb in group H and group D, which with shorter clinical history of type 2 diabetes. But there were significant differences in group H and groups E and F, which with longer duration of diabetes. The absorbance values of Hb located at 276 nm have shown a trend of increasing along with the extension of clinical history in groups D, E and F. However, the absorbance values of Hb located at 414 nm, 540 nm and 576 nm have shown a completely opposite trend. Comparing to groups H and D, content of α-helix secondary structure has significantly decreased, while content of β-sheet secondary structure has significantly increased in groups E and F(P<0.05). It showed that as clinical history extending, the secondary structure of Hb in diabetics has changed. Conclusion(1) Occupational labor intensity, personal diet behavior, and obesity were related to the pathogenesis of type 2 diabetes(P<0.05). Increasing the occupational labor intensity appropriately could reduce the onset risk of type 2 diabetes. However, unhealthy personal diet behavior and obesity might increase the onset risk of type 2 diabetes mellitus.(2) It implied that a high Hb A1 c level might be an important factor in influencing Hb structure in type 2 diabetics.(3) It implied that the clinical history might be an important factor in influencing Hb structure in type 2 diabetics. |
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